The present invention is directed generally to a device for alerting the driver of a rearwardly moving vehicle to the presence of any object in close range behind the vehicle. More particularly, the present invention is directed to a micro-wave radar device using the doppler shift principle to detect the presence of a moving target within the transceiver range.
Drivers of motor vehicles have always had a certain degree of difficulty with backing up their vehicles. Whereas this is due partly to the different steering response of a rearwardly moving vehicle, most backing-up accidents are due to the driver's limited visibility. Many trucks have a considerable blind spot directly rearwardly of the vehicle which is not visible through side mounted mirrors. But even in smaller trucks and passenger cars with rear windows, there may be blind spots at the rearward corners of the vehicle and below the driver's line of sight.
Devices have previously been known for detecting the presence of objects behind a vehicle but such devices have not achieved widespread usage. Devices which provide an audible alarm directed rearwardly of the vehicle are ineffective if a child, for example, in the path of the vehicle does not react to the alarm and if the vehicle driver does not hear the alarm. Certainly an external alarm will not remove stationary objects from the path of the vehicle.
Accordingly, an object of the invention is to provide an improved device for alerting the driver of a rearwardly moving vehicle to the presence of a person or object within a short range distance behind the vehicle.
Another object is to provide such a device with a remote audible alarm suitable for placement within the passenger compartment of a vehicle.
Another object is to provide such a device which employs micro-wave radar technology.
Another object is to provide a driver alerting device which may be easily electrically and mechanically connected to a vehicle.
Finally, an object is to provide a driver alerting device which is economical to manufacture, simple and rugged in construction and efficient in operation.